Horse Sense: In the past couple years, one of the hottest trends in the Mustang world has been the adornment of the interior and engine compartment with billet-aluminum aftermarket replacement pieces. At $25-$150 for the average add-on, these pieces are affordable eye candy for the owner, passenger, or car-show judge.

When do you stop? When have you added enough power, tweaked the suspension just right, and massaged the look to the point that it halts traffic? Those are the questions that face the top Mustang builders in the hobby. Now, if you're assembling a Mustang to dominate a heads-up class, some of those questions can be answered by how you stack up against your closest competition. But if you're building a show car, how do you know when you've crossed the line from perfect street stomper to overblown nut job? Yes, things can be tough on the car-show circuit, but when you get it just right, your success can be measured in trophies won and smiles granted to the onlookers.

The Mustang super-enthusiast whose handiwork you see here is Scott List, a 48-year-old electrical distributor from Greenville, Ohio. He took delivery of his delicious '98 Cobra on Valentine's Day of that year, and it's been a labor of love ever since.

"When I started out," Scott says with youthful enthusiasm, "I knew I was going to modify." His goal was to have "a car that looked darn good and ran better!" And so the modifying began with some of the premier shops in the aftermarket industry.

His first stop was at Steeda, which did the Vortech blower and a complete race-inspired, G-Trac suspension. A Steeda heavy-duty radiator and 3.73 gears were added to make sure everything worked well together. A year later, Scott and his wife, Cheryl, were back for brake upgrades and the R hood. After a string of T45 failures, Sean Hyland Motorsport installed the bulletproof Tremec T56 trans in September 1999-it's held together ever since.

After some success on the car-show circuit, Scott became interested in open-track events. He took driver training courses at Gingerman Raceway in Michigan and Track Days at Road Atlanta. He plans to ultimately enter the car in the hot NASA American Iron series that's sweeping the nation. This means all those beautiful add-ons may be placed back in their boxes as Scott looks to pare weight from the Cobra for competition's sake.

So, it looks as if even Scott has found his limit. As the car sits, it's a show car, a road rocket, or whatever he wants to make of it. It's extreme enough to win trophies but also competitive enough to set lap times. Along the way, the Cobra has helped Scott become addicted to the road-course way of life. The next time you see this car, it will probably still have the attention-getting goodies on it, but maybe with just a little more serious underpinnings. Regardless, Scott has assembled a classic example of how Mustangs can continue to evolve no matter how much you put into them. After all, when is too much of a good thing really too much?

You can tell there's been a lot of time spent on the interior. There are Auto Meter gauges, an A-pillar pod, a carbon-fiber dash kit, an FR500 steering wheel, and more billet add-ons and doodads than you can shake a snake at! However, this Cobra becomes more "race car" every year, and that's just how Scott likes it. Tom Honsaker from Paul's Automotive Engineering installed the Kenny Brown cage, the Simpson five-point harnesses, and the Maximum Motorsports' full-length subframe connectors. The Steeda Tri-Ax shifter is attached to an SHM-prepared T56 six-speed box-the only thing Scott has found that will stand up to the extra grunt of the blown four-cammer. A King Cobra clutch clamps the power from the billet steel flywheel. The aluminum FRPP driveshaft sends the power to a stock rearend that houses 3.73 gears.